Schedule 40S Pipe 2 1/2 Inch (DN65) is a stainless steel pipe reference size identified by both its NPS designation and metric DN equivalent. This page brings the key dimensional and weight information together for engineers, drafters, fabricators, estimators, and procurement teams.
Use the existing table as the primary dimensional reference, then confirm material grade, manufacturing requirements, end preparation, tolerances, and project specifications before ordering or detailing the pipe. The schedule designation describes the dimensional series; it should not be treated as a complete material or pressure-design specification.
Schedule 40S Pipe 2 1/2 Inch (DN65) is a stainless steel pipe size commonly used in industrial piping systems that require corrosion resistance, dependable wall thickness, and reliable flow capacity. This pipe size is often used in process plants, utility systems, water treatment projects, and stainless steel fabrication work.
This dimension data is based on ANSI/ASME B36.19, which is the standard commonly used for stainless steel pipe dimensions.
2 1/2 Inch Schedule 40S Pipe Dimensions
- Pipe Schedule: 40S
- Nominal Pipe Size: 2 1/2 Inch
- DN Size: DN65
- Outside Diameter (OD): 73 mm
- Inside Diameter (ID): 62.68 mm
- Wall Thickness: 5.16 mm
- Pipe Weight: 8.63 kg/m
- Pipe Weight Including Water: 11.71 kg/m
- Standard: ANSI/ASME B36.19
Schedule 40S Pipe 2 1/2 Inch Dimension Table
| Pipe Schedule | NPS (Inch) | DN (mm) | OD (mm) | ID (mm) | Wall Thickness (mm) | Weight (kg/m) |
|---|---|---|---|---|---|---|
| 40S | 2 1/2 | 65 | 73 | 62.68 | 5.16 | 8.63 |
What Is 2 1/2 Inch Schedule 40S Pipe?
A 2 1/2 inch Schedule 40S pipe is a stainless steel pipe with a nominal size of 2 1/2 inches and a wall thickness defined by the 40S schedule. For this size, the outside diameter is fixed at 73 mm, while the inside diameter is 62.68 mm based on a wall thickness of 5.16 mm.
The letter S in 40S is commonly used for stainless steel pipe dimensions under ASME B36.19. This designation is widely used by engineers, fabricators, and procurement teams when selecting stainless steel piping for industrial service.
Where Is Schedule 40S Pipe 2 1/2 Inch Used?
This pipe size is commonly used in systems that need both good flow capacity and the corrosion resistance of stainless steel. Typical applications include:
- Process piping in industrial plants
- Water treatment and utility systems
- Food and beverage piping lines
- Chemical service piping
- Stainless steel branch and service lines
Why Pipe Dimensions Matter
Accurate 2 1/2 inch Schedule 40S pipe dimensions are important for piping layout, fabrication, support design, transport planning, and material takeoff. Engineers and designers often check OD, ID, wall thickness, and weight before selecting flanges, fittings, supports, and installation methods.
The outside diameter is important for matching clamps, flanges, and pipe supports. The inside diameter helps estimate flow area and system capacity. The wall thickness is important for specification compliance and mechanical strength, while the pipe weight per meter is useful for structural loading, support design, and handling calculations.
2 1/2 Inch Schedule 40S Pipe Weight Information
The nominal weight of this pipe size is 8.63 kg/m. When filled with water, the combined weight becomes approximately 11.71 kg/m. This information is useful for lifting plans, support design, and pipe rack load calculations in industrial projects.
Difference Between NPS 2 1/2 and DN65
NPS 2 1/2 is the inch-based nominal pipe size, while DN65 is the metric designation used in international drawings and specifications. Both terms refer to the same nominal pipe size, and users may search by either inch or DN format depending on project standards.
Common Search Terms for This Pipe Size
Users may also search for this pipe using related keywords such as 2 1/2 inch Schedule 40S pipe dimensions, DN65 Schedule 40S pipe dimensions, 2 1/2 inch stainless steel pipe weight, DN65 pipe dimensions, or DN65 sch 40s pipe dimensions.
Conclusion
Schedule 40S Pipe 2 1/2 Inch (DN65) has an outside diameter of 73 mm, an inside diameter of 62.68 mm, a wall thickness of 5.16 mm, and a weight of 8.63 kg/m. It is a useful stainless steel pipe reference size for design, drafting, fabrication, and procurement work.
This page provides a quick reference for engineers, drafters, fabricators, and buyers who need reliable 2 1/2 inch Schedule 40S pipe dimensions and DN65 pipe dimensions in one place.
How to Read This Schedule 40S Pipe Reference
The page reports the pipe’s nominal size, DN designation, outside diameter, inside diameter, wall thickness, and mass per unit length. These values serve different purposes during design and drafting. The outside diameter is commonly checked when coordinating supports, clamps, fittings, and connection details. The inside diameter is useful when reviewing flow space and hydraulic calculations. Wall thickness supports dimensional checks and specification review, while weight helps with handling, support reactions, and preliminary pipe-rack loading assessments.
NPS and DN are nominal designations rather than interchangeable measurement units for every physical dimension. A drawing may identify the line as NPS 2 1/2, DN65, or both. Keeping both designations visible can reduce confusion during procurement and coordination with metric project documentation.
Checks to Make Before Using the Data
- Confirm that the pipe is stainless steel and that the required material grade is specified separately.
- Check the selected pipe fittings, flanges, valves, and branch connections for compatible nominal size and connection requirements.
- Use the reported weight as a reference for planning, then account for insulation, valves, fittings, contents, supports, and project-specific loads where applicable.
- Do not infer a pressure rating from the schedule alone. Pressure design also depends on material, temperature, code requirements, corrosion allowance, joining method, and other engineering inputs.
- For CAD or drafting work, compare the selected component library file with the project’s piping specification and connection details.
Related Pipe and Piping References
For a broader design workflow, compare this page with related references for stainless steel pipe schedules, NPS and DN pipe size conversions, pipe wall thickness, pipe fittings, and pipe flange dimensions. These topics help connect the dimensional table to layout, fabrication, and procurement decisions without treating one pipe entry as a complete piping design.
Frequently Asked Questions
What does 40S mean in this pipe designation?
40S identifies a stainless steel pipe schedule designation associated with the dimensional reference used on this page. It does not, by itself, identify the stainless steel grade or establish a complete pressure rating.
Are NPS 2 1/2 and DN65 the same nominal pipe size?
Yes. NPS 2 1/2 is the inch-based nominal designation, while DN65 is the metric designation used for the same nominal size. The actual dimensional values should be taken from the applicable pipe reference and project specification.
What is the difference between pipe weight and pipe weight including water?
Pipe weight describes the pipe itself. Pipe weight including water combines the pipe reference weight with the stated water-filled condition. Other contents, insulation, coatings, fittings, and supports require separate consideration.
Can the dimensions on this page be used to select a pressure rating?
No. Dimensions are only one part of pressure-system design. Material grade, design temperature, code requirements, corrosion allowance, fabrication details, and project criteria must also be reviewed by the responsible engineer.
Where can the associated CAD file be used?
The downloadable DWG can support preliminary drafting and layout coordination. Review its geometry and connection details against the project piping specification before using it for fabrication or construction documentation.